Volti Audio Razz loudspeaker Measurements

Sidebar 3: Measurements

For logistical reasons, I measured a different sample of the Volti Audio Razz (serial number V1, 007) to those auditioned by Tom Gibbs. (There wasn't a grille supplied with this sample.) I measured the loudspeaker's farfield behavior with DRA Labs' MLSSA system and a calibrated DPA 4006 microphone. I used an Earthworks QTC-40 mike for the speaker's nearfield responses. I repeated some of the testing with Dayton Audio's OmniMic V2 and DATS V2 systems.

Volti specifies the Razz's sensitivity as "97dB." My estimate was 93dB(B)/2.83V/m—while this is lower than the specification, it is still much higher than average. Although the Razz's nominal impedance is specified as 6 ohms, the magnitude (fig.1, solid trace) rarely drops below 8 ohms. The average impedance is around 12 ohms, though there is a minimum value of 4.1 ohms at 100Hz. Though the electrical phase angle (dashed trace) is occasionally high, the magnitude is also high at the same frequencies, which ameliorates the Volti speaker's demand for current. There is an exception at 90Hz, however, when a magnitude of 5.5 ohms is coupled with a capacitive phase angle of –39°. The EPDR (equivalent peak dissipation resistance) calculated with the formula in a 1994 AES paper by Eric Benjamin, is generally 4 ohms or higher but it does drop to 2 ohms between 85Hz and 95Hz. Although Volti recommends using their 8 ohm output taps, tube amplifiers will probably work best with the Razz from their 4 ohm taps, as music can have high energy in the mid-bass region.

720VoRazzfig1

Fig.1 Volti Razz, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

Discontinuities in the impedance traces at 180Hz and 305Hz imply the presence of resonances of various kinds. When I investigated the enclosure's behavior with a plastic-tape accelerometer, the only vibrational mode I found was at 305Hz, which was present on all the walls but was very low in level (fig.2). A very small amount of flexing at 100Hz can also be seen in this graph, but the large cabinet appears to be well-braced.

720VoRazzfig2

Fig.2 Volti Razz, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of sidewall level with woofer (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The saddle at 44Hz in the impedance magnitude trace suggests that this is the tuning frequency of the Razz's port. This was confirmed by the fact that the nearfield response of the woofer (fig.3, blue trace) has its minimum-motion notch at the same frequency, which is when the back pressure from the port resonance holds the cone stationary. The woofer's output peaks sharply at 100Hz. This will be due in part to the nearfield measurement, which assumes the drive-unit is mounted in a baffle that extends to infinity in both planes. However, the amplitude of this peak does suggest that the woofer's alignment is underdamped. The nearfield response of the port (red trace) peaks between 35Hz and 70Hz, but the port's upper-frequency rolloff is disturbed by a major peak just below 200Hz. This is the same region as the other discontinuity in the impedance traces.

720VoRazzfig3

Fig.3 Volti Razz, acoustic crossover on tweeter axis at 50", corrected for microphone response, with the nearfield responses of the woofer (blue) and port (red), respectively plotted below 1kHz and 600Hz.

The woofer's output above 100Hz is relatively even, and the crossover frequency between the woofer and the horn-loaded midrange unit (fig.3, green trace) appears to be set at 500Hz, with symmetrical slopes that are close to third-order in nature. The output of the midrange unit is also even up to 3.5kHz, but above that frequency the Volti's output is both tilted up and marred by a series of sharply defined suckouts. Although it wasn't possible to drive the midrange unit and tweeter individually, I did investigate this behavior by blocking each drive-unit in turn while I measured the other. It appears that while the two upper-frequency drive-units cross over around 5.5kHz, either the crossover filters are slow-rolloff types or the designer has relied on the drivers' natural low- and high-pass behavior. The result is that there is significant overlap of their outputs between 3kHz and 13kHz. The suckouts are therefore due to the fact that the acoustic center of the horn-loaded midrange unit is several inches behind that of the tweeter. There is destructive interference at frequencies where this distance is equivalent to an odd number of half-wavelengths, the so-called comb filter effect.

The black trace below 300Hz in fig.4 shows the sum of the Razz's nearfield woofer and port outputs, taking into account acoustic phase and the different distance of each radiator from a nominal farfield microphone position. The apparent rising response below 500Hz will again be partly due to the nearfield measurement technique, but some of the rise is real, which I confirmed with a farfield measurement. The upper bass region is disturbed by a dip centered on 145Hz, and the Razz rolls off with the usual fourth-order reflex slope below 45Hz. This is a relatively high frequency for a large speaker, but there is always a tradeoff between low-frequency extension and sensitivity.

720VoRazzfig4

Fig.4 Volti Razz, anechoic response averaged across 30° horizontal window centered on the tweeter axis at 50", corrected for microphone response, with the complex sum of the nearfield woofer and port responses plotted below 300Hz.

The Volti's farfield response, averaged across a 30° horizontal window centered on the tweeter axis, is shown as the black trace above 300Hz in fig.4. The response trend is relatively even between 500Hz and 3kHz, but above that frequency the rising response, disturbed by interference peaks and dips, is again evident. How audible the speaker's behavior in the top two audio octaves will be will depend on how directional it is. The plot of the Razz's dispersion in the horizontal plane, referenced to the response on the tweeter axis, is shown in fig.5. The apparent peaks to the speaker's sides are mostly due to the on-axis suckouts filling in to some extent, but this graph also shows that the Razz becomes very directional above 10kHz, which will work against the excess of energy on the tweeter axis. The horn-loaded midrange unit also becomes relatively directional in the low treble. In the vertical plane (fig.6), the Razz's tweeter-axis balance is maintained over a ±5° window. (The tweeter is 38" from the floor.)

720VoRazzfig5

Fig.5 Volti Razz, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

720VoRazzfig6

Fig.6 Volti Razz, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 15–5° above axis, reference response, differences in response 5–15° below axis.

In the time domain, the Volti Razz's step response on the tweeter axis (fig.7) reveals that all three drive-units are connected in positive acoustic polarity. The tweeter's output arrives first at the microphone, with that of the midrange unit following 0.7ms later and that of the woofer 0.5ms after that (footnote 1). The decay of the midrange unit's step does smoothly blend with the beginning of the woofer's step, which implies good crossover implementation. The Razz's cumulative spectral-decay plot (fig.8) is difficult to interpret because of the time delay between the upper-frequency drive-units' outputs. However, it appears that, other than the interference effects between their outputs, the decay in the midrange and mid-treble region is relatively clean. However, because of the slow upper-crossover slopes, the midrange-unit output has some ridges of delayed energy above 10kHz.

720VoRazzfig7

Fig.7 Volti Razz, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

720VoRazzfig8

Fig.8 Volti Razz, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

The Volti Razz's measured performance suggests that its treble balance can be adjusted by experimenting with toe-in. The manner in which its impedance magnitude smoothly drops from just over 18 ohms in the midrange to 6 ohms at the top of the audioband also suggests that the rise in the speaker's high-frequency on-axis response will, to some extent, be countered by using a tube amplifier's 8 ohm tap, which will offer a higher output impedance than the 4 ohm tap. The treble might also be subjectively balanced by the Volti's somewhat excessive lows. Overall, while the Razz has an impressively high sensitivity—it will play loud with only a few amplifier watts—this achievement must be measured against the maxim TANSTAAFL (footnote 2), which I first came across in the 1960s in a book by the late science-fiction writer Robert Heinlein, The Moon Is a Harsh Mistress.—John Atkinson


Footnote 1: In the on-line comments that accompanied the late Art Dudley's review of the Klipschorn AK6 in September 2019, a reader conjectured that with a loudspeaker that behaves like this in the time domain, the outputs of the drive-units could be brought into time alignment with DSP and tri-amping. However, Volti's Greg Roberts commented that doing so can detract from the essential sound quality offered by a horn loudspeaker. Greg wrote "I tri-amped and digitally time-aligned my own Khorns back in 2009 and I quite enjoyed it for a while. The time-alignment was a noticeable improvement. But the complexity of the system took something away that I missed and I went back to passive crossovers and a really nice tube amplifier and a simpler system and I enjoyed that a lot more."

Footnote 2: There Ain't No Such Thing As A Free Lunch. In his 1961 book Stranger in a Strange Land, Heinlein also introduced me to the concept of a "Fair Witness," something I try to emulate in these measurements sidebars.

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ARTICLE CONTENTS

COMMENTS
funambulistic's picture

I should have known JA1 was a Heinlein fan! "Fair Witness" is a really neat concept, like a notary on steroids...

ejlif's picture

how these compare to the klipsch cornwall IV

Volti's picture

But the Volti Audio Rival would be the more natural choice to compare to the Cornwall IV.

I had a pair of Cornwalls many years ago and really enjoyed them. They fit nicely in front of my Khorns, without interfering with the output from the Khorns - something I learned from New England Music Company in Waterville, Maine back in the late 70's. That's how they had them set up in the demo room.

The Cornwall IV midrange horn looks to me like it would be so much better than the miserable little horn that was used in the first CW iteration. But I have my suspicions that there's a $26 Chinese-made midrange driver with a metal diaphragm attached to it.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

Also, take a look at Klipsch Forte III, review and measurements by Stereophile ...... Forte III also cost less, $4,000/pair :-) .......

Volti's picture

The Klipsch Forte III is a good speaker, but when you want a higher build and finish quality, and better bass, and a more refined sound, the Razz offers all of that.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

Did any young people listened to your Razz loudspeakers and liked their sound? ...... Most of the young people, say in their 20's and 30's, can hear up to 20 kHz ...... Did those people like the treble reproduction? :-) .......

Archguy's picture

However there's next to no musical information above 16khz, even harmonics..

John Atkinson's picture
Archguy wrote:
However there's next to no musical information above 16khz, even harmonics.

That's not actually correct, as some some musical instruments can have harmonic content well above 20kHz. See my article on this subject starting at www.stereophile.com/features/282/index.html. You also need an extended bandwidth to correctly reproduce transients.

John Atkinson
Technical Editor, Stereophile

blang11's picture

I love that track.

funambulistic's picture

Shhh - don't tell any audiophiles. They might ruin it...

Anton's picture

Thank you for the review.

In the recent Klipsch reviews, there was discussion about the lack of time alignment between drivers, did you notice anything similar with these speakers?

jimtavegia's picture

I am sorry, but for $20K someone needs to go back to the drawing board and to think that one needs to buy some DSP tools to fix an expensive speaker like this makes no sense to me. There are many speakers well under $10K that out perform this.

I am sorry if this sounds mean-spirited, but I am tired of underperforming, expensive gear. I'll put my near 40 year old AR-58's up against this.

jimtavegia's picture

Even at $5K my comments still stand.

Volti's picture

It's very simple, stop looking at the graphs, and use your ears. That's how to really Have Fun!

Greg Roberts
Volti Audio

jimtavegia's picture

Is it from some reflections from the horn as that has surely got be audible. If this was from any other audio component there would be questions asked. I am not trying to offend.

Volti's picture

anomalies of the mid to tweeter interaction in a post below.

Greg Roberts
Volti Audio

SNI's picture

It is not that simple.
If you really can measure low distortion in a given speaker, you´ll always know, that this is the thing to strive for.
There is no free lunch out there sadly.
Not said that you allways can just look at measurements, but they really do give you some kind of impression of strenghs and weaknesses.
In this particular case, there might be reasons to love for afficionados, but there sure is a lot to dislike for those who strives for high fidelity sound.

JamesAlan's picture

They are $5k + $1k for the red gum veneer.

Volti's picture

Just thought I should address the FR anomalies that show up in the test measurements so you understand where those come from.

I am using a mid driver that also covers up into tweeter territory. I have tried and can easily make a filter that will cross-over the mid and tweet very neatly by using an inductor on 'top' of the mid.

During the development of any of my speakers, I 'bread-board' the crossovers in front of me on a table, with both speakers set up for music listening. I'm able to run test measurements and then switch over to music and play with the crossover components on the fly. It's a great way to listen to the different filter changes and then measure to see where I'm at. It's my way of doing things.

On the Razz, I found that I enjoyed the sound of the midrange better when I removed the filter from the top and just let it run into the tweeter. Every time I made this change with music playing and then ran a test measurement I could see that the measurement looked terrible. But I couldn't ignore the fact that it sounded better to me.

So I decided to go with what sounded best to me, not what measured the best.

If you're one of those people who cannot accept a speaker that measures bad, Volti Audio speakers are probably not for you. You have lots of choices out there for speakers that measure good, so you don't need to be messing around with mine.

But if you're one of those people who use your ears and listen to speakers, and appreciate the effort that designers like me put into listening during development, then you'll probably be like most people who come into my room at the audio shows and are really blown away by how great the Volti Audio speakers sound.

A company like Volti Audio doesn't last in this business if they are not making great sounding speakers that people love. I'm proud of my ten years of success in the audio business, and I plan to continue what I'm doing for many more years. I'm going to do it MY way, which is the only way I can. It's how I steer my passion into my art.

So you'll probably see a lot more bad measuring Volti Audio speakers in the future that my customers, audio reviewers, and audio show listeners absolutely love. And I'm sure you 'measurement first' guys will continue to be baffled by how it can be this way.

I'm smiling a big smile as I write this.

Trust your ears and Have Fun!

Greg Roberts
Volti Audio

Anton's picture

As I recall, the Rectilinear speaker line did something similar regarding crossovers and the reviews of the time reminded me of what I've heard from other Volti speakers when I have listened at shows...

From past Rectilinear reviews...

"Their Model IIIs are the finest loudspeakers I've ever listened to, regardless of size, type, or price. They produce beautiful bass tones without boom, accurate midrange tones without a trace of coloration, and crystal-clear treble tones without hint of harshness. And they do it at any volume, including "window-rattling" sound levels."

Ronald M. Benrey, Popular Science Monthly, May 1968

"I've heard them all, but your Rectilinear III speakers are really wonderful! The sound is so natural that I feel that I am sitting in there right with the band. I am so very pleased with these speakers that I feel you should know about it."

Duke Ellington, in letter to the company dated 4 November 1966

___

I think those statements fit with what I've experienced with the "Volti sound."

___

Side note: It has always been pleasant meeting Volti people at shows...I even like your play list. The acoustic solo version of Boz Skaggs doing a slow "Lowdown" sounded superb.

Bogolu Haranath's picture

Did they play any solo piano music? :-) .......

Volti's picture

I don't know who 'they' are, but I can tell you, as a piano player myself, that the Razz speakers reproduce the proper tone and weight of each piano note as accurately as the piano is recorded.

I find that it's much easier for a system to reproduce a piano recording than it is for the engineers to properly capture the sound of a piano on a recording. In other words, when I find fault with a solo piano recording, it's typically the recording and not the system playback. The piano is a very difficult instrument to properly record.

That doesn't mean that all systems playback piano with great accuracy because some don't. I've heard many speakers make a piano sound like a toy. The Razz do a great job of making you believe there is a real piano being played by a person in front of you. The Rivals do it better, and the Vittoras are in another league.

One thing about listening to a solo piano recording, there is perhaps nothing of greater importance to me than making sure the volume level is set to be at the same level as what a real piano would be about ten feet in front of me. This is what horn speakers are all about - reproducing as close as possible what the actual instrument sounds like, and while electronic music mixes can vary in volume over a wide range, to believe there's an acoustic piano in front of you, you've got to get the volume level right.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

Take a look at FR, Fig.4 in measurements section ...... There is -10 dB drop from 100 Hz to 1 kHz ...... and, raise of +10 dB from 1 kHz to 20 kHz ........ That looks like the 'Fletcher-Munson' curve (equal-loudness contour) ....... Does 'getting the volume levels right' has anything to do with that frequency response? :-) .......

Volti's picture

want the midrange to be any louder, trust me. Nobody would sit in front of my speakers and say the midrange is not loud enough.

So I wonder if there's something about the directivity of a midrange horn that shows up differently in the testing than a standard cone midrange. I'm a horn guy and I have no experience testing standard box speakers that are supposedly flat or near flat through the entire bandwidth.

There must be something to this that has yet to be defined, because I can very easily flatten out the FR of my speakers and I've done it, and it is not at all what you would want to listen to in your room. There isn't a single person reading this right now who would like the sound of the Razz with a flat frequency response. You would say it was WAAAYY out of balance and WAAAYY too much midrange.

There is a reason for the curve you are seeing, but I can't explain it except to say it's what sounds right to me and my customers and audio reviewers and audio show-goer's etc...

Again I'll point out to all of you here, Volti Audio could not maintain a successful business as we have for ten years now if our speakers sounded as bad as the measurement-first guys here would have you believe. It just doesn't happen. You can't be in this relatively small business and continue year after year to get rave reviews and have such happy customers if there is a problem.

In fact, it takes a lot more than just average to make even five years in this business. I've seen a lot of average come and go in the ten years I've been at it. I feel very fortunate that what I like for a sound, others do too, because it might not have been that way. I very easily could have been one of those guys who thought I had something really great - something that I was really passionate about, and yet couldn't sell my product. Very fortunate and very grateful that I'm able to continue doing something that I love to do and make a living at it.

And it's very simple to explain, it's about great sound, great build quality, and beautiful finish work - the measurements just don't matter.

Greg Roberts
Volti Audio

Roger That's picture

I understand and agree when you say “In other words, when I find fault with a solo piano recording, it's typically the recording and not the system playback.”

The problem is that the same principle applies most recordings (electronic instruments included), because there’s an historical lack of standards on mixing and mastering monitors and setup (room included).
How can you (or anyone) judge the tonal balance of a piano recording without knowing the whole context?

Maybe the recordings you’re using as references (I don’t mean “You” literally, as this can be applied to other loudspeaker designers and even to reviewers) were made/mix/mastered on monitoring equipment and conditions that are more similar to how your loudspeakers sound in your room.

When that happens, a recording that will sound great on a more natural loudspeaker (maybe because it was mastered in something closer to that) will sound like a toy piano on yours (we’re just “rotating” the perspective here).

That’s when trying to achieve something closer to neutrality has an added value, imho.

I do understand that many of those FR anomalies won’t be a real issue on some circumstances, except for that (very hard to understand) bass response.

The majority of rooms will introduce more (and often more pronounced) problems than that 12dB dip followed by an 8dB peak in the bass region, but the chances of that working in a constructive way with a room are minimal at best.

These days it should be expected from any loudspeaker design to have a relatively smooth bass response (even if it is slightly tilted in one way or the other).

As a piano (and bass guitar) player myself, I’m sure you understand how the human ear can differentiate more accurately peaks and dips at those frequencies (that coincide with musical notes, bass drums tuning and other things) than the same peak and dip at (let’s say) 8.000Hz and 8.060Hz (considering the same wavelength spacing).

I could go on, but I don’t want (in any way) to devalue any of your work and results, and I honestly believe that the market certainly has a place for the older school of loudspeaker design (by this I mean not focusing on getting a smooth off-axis response, textbook bass alignment, trying to keep comb filtering as low as possible, etc).

I sincerely wish you the best success with your company and business, both for yourself and all consumers (diversity is in itself hugely desirable).

The reason for my comments are mostly linked to the fact that Stereophile is a reference in reviews (in my book and several other people, I believe) because it brings us _a broader picture_ (both subjective listening reviews and measurements).

I don’t “believe” in subjective listening reviews alone (at least not any more than I don’t judge a loudspeaker by its measurements alone), because one without the other gives a very vague and faded picture of how it really performs “natively”.

Some Sterophile reviews include an in-room averaged response around the listening positions, and sometimes it helps to explain the perception of the reviewer.
Given that it surely demands additional logistics, that isn’t always possible (plus these strange times that we live in).

And that’s probably why you’ll see more comments on measurements here than (likely) anywhere else.

Many Stereophile readers (myself included) are used to some degree of correlation between both aspects of the review.

Again, I wish you all the best and it wouldn’t be the first time that I would buy something that (on paper) I felt that it wouldn’t be the "right" product for me. ;)

Roger

Bogolu Haranath's picture

The HF response from 3-4 kHz and up, looks like 'Comb filter' effect :-) ......

Volti's picture

"How can you (or anyone) judge the tonal balance of a piano recording without knowing the whole context?"

I'm not trying to judge the recording. I know what a piano sounds like.

Greg

Jim Austin's picture

Hey Greg, thanks for posting, but please remember to include your industry affiliation in your posts.

Of course that goes for everyone.

Best Wishes,

Jim Austin, Editor
Stereophile

Roger That's picture

Knowing how a piano sounds doesn’t tell you at all if the loudspeaker is being correct and natural or not.

If the monitors (and/or headphones) that were used to not only place the microphones around the piano (but often also to make the choice the "right" microphone model for those recording conditions) have a specific sound signature that are less than neutral (like many are), chances are that the loudspeakers that will have similiar deviations from neutrality (like those monitors) will sound more realistic.

That’s why you often hear different piano recordings sounding more or less realistic with a particular set of loudspeakers, while other recordings benefit different loudspeakers.

This is what is well-known as “the circle of confusion”, and in the end gives the opportunity for so many loudspeaker designs (amplifiers and most digital sources don’t have 1/50 of that “slack”).

In the absence of a very solid engineering and testing procedures, the voicing is still made by ear with a set of recordings that someone elected as being “the right ones”, which again is a purely personal preference.

That’s not to say that there’s no validity on that approach (because I truly believe that there is), but IMHO, science combined with human hearing (perception) is the way to go forward, and not the more than a half of century argument of “I know how a _insert musical instrument here_ sounds", especially without knowing or hearing how the recording sounded on the original equipment used to judge and fine tune it.

Bogolu Haranath's picture

You (GR) probably could eliminate that tweeter ..... The 2" upper midrange horn loaded driver could go up to 10 to 15 kHz and then drop off ....... That tweeter is producing all that HF serrated appearance in the FR ...... Of course, you could also get a better measuring tweeter :-) ........

Volti's picture

You don't have any idea what you're talking about regarding my speaker design. Of course I think you know that and you're just trying to egg me on. No problem, I'll use it as another opportunity to market my product.

You haven't heard the Razz, you haven't tested the Razz, you have no idea what drivers I'm using, and most importantly, you're not designing my speakers for me, so you have no idea what kind of sound I'm aiming for.

The Razz tweeter happens to be the second best sounding high-sensitivity tweeter I've ever heard. There aren't that many on the market you know - compared to lower sensitivity tweeters, which are plentiful, and often sound very smooth, with extended high frequencies.

It's very difficult to find a high-sensitivity tweeter that has 'air' and upper end extension, without the nasty and harsh sounding 8Khz - 10Khz peak that most HS tweeters exhibit. (think PA tweeters) - that's what most horn speakers on the market have for a high frequency sound.

It has cost a lot of money and time over the years to do it, but I have been fortunate to discover two examples that work really well in my designs.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

That HF response in the measurements section could be a 'turn-off' for some potential buyers ..... I don't know whether you are familiar with Eminence drivers or not ...... They sell a couple of 2" horn loaded drivers which have 110 dB sensitivity ...... Those upper midrange/ HF drivers go up to 10 to 15 kHz and then drop-off ..... They also sell 1" horn loaded drivers which have similar high sensitivity ..... See their website for details ...... I'm not affiliated with Eminence ...... One of the pro audio/car audio dealers I know uses them ..... Eminence drivers are used by several pro audio speaker manufacturers :-) ......

Volti's picture

So they simply won't buy my speakers will they? I don't have a problem with that.

I'm not trying to build speakers for everyone. I'm focused on a particular sound that I like, and I'm fortunate that I have plenty of customers who also like the sound of my speakers. That's what keeps Volti Audio going.

Another thing people might find interesting. I have no interest in growing my company larger. I find that people often assume that when you're in business, you are always looking for more and more. People will say to me that Volti Audio will be the next Klipsch. Ha!! No way that's happening - not under my watch anyway. You couldn't pay me enough to take on the stress of having to pay for the overhead they have to keep the business running.

The audio business for me is a lifestyle choice as much as it is a business of building speakers. I really enjoy getting up in the morning and going out into my shop to make sawdust. I don't make nearly the money I used to in the Home Construction business I had for 25 years, but I can honestly say I'm a much more relaxed and happy person these days.

If you took the money out of the equation completely, I would still get up every morning and go design and build Volti Audio speakers. I'm a lucky guy to be able to say that. Some of you reading this really understand what I'm saying.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

Accuton makes a 2" ceramic dome upper midrange/HF driver, which has approx. 95 dB sensitiviity, available at Madisound ....... Of course, Accuton ceramic drivers are expensive :-) ......

johnnythunder's picture

measurement "experts" who continually chime in about the sound quality of a component without LISTENING to them first. I own components by a brand that has not measured well in the pages of Stereophile. I love the sound of them and wouldn't change a thing based on my budget. The proposed comparison with Revel speakers shows a tremendous amount of ignorance on behalf of the proposer. All they have in common is the price. Those speakers couldn't be more different. Those that enjoy Revel speakers can delight in them all they want. They sound (and look) like bright, home theatre speakers to me. No comparison to a handmade speaker like the Voltis.

Volti's picture

but I know going into this that there are AHs in the world and on the internet they show their true colors with zero repercussions. Just like those who think measurements of speakers tell you how the speakers sound, they are a small minority of the group that is here reading all this.

I try to stay positive and use my time to further explain my position, which ends up being a form of marketing. Everyone who reads about me knows who I am. I'm an open book. I really 'put myself out there' - it's part of how I market myself. My cell phone number is on the internet! You can't get much more open than that.

Greg Roberts
Volti Audio

SpeakerScott's picture

I've just read through the whole thread. Look, I get it...a razor flat on axis response isn't an indicator that you'll like a speaker. It's an indicator of the engineering folks knowing how to design crossovers that take into account the complex impedance of the drivers and combines the acoustical and electrical transfer functions to yield a flat response.

At the next level of engineering capability the designers will juggle vertical/horizontal polar responses, overall power response, group delay, distortion.

Based on the fact that you meticulously pointed the speakers to control the listening axis...you're more than aware of the issues involving the power response.

The overlap of those tweeters surely contribute to a sense of space, but having experienced similar situations with series first order crossovers and/or wide spacing with drivers....it can sound alluring and fun...but rarely accurate.

I also find it intriguing that Tom has Zu Audio Omen's...these aren't what I would call neutral by any means. The ear has a notoriously short memory...but there's no way that Tom is coming into this interview with an unbiased opinion.

Having designed a bunch of horn speakers for both PA and home speakers, the issues that are in these measurements are solvable. Relatively easily. It's not that hard to keep those tweeters apart from each other. It's not that hard to get a port that doesn't show a pipe resonance that strong.

And you can do it without losing the character of dynamics, tonality and sensitivity that you love. You and John are much farther apart in sensitivity measurements between your speakers...I can't help but suspect that some of the issues in the speaker are present because the measurement protocol you use isn't sufficient to spot the issues...or if they are...you're willfully allowing them through.

-Scott
facebook.com/DIYRM

Tom Gibbs's picture

Nice review, Ken, but I still can't freaking believe that after you and I both raved in the pages of Stereophile about the astonishing musicality and scale of realism offered by the Volti Razz loudspeakers -- especially when driven by tube amplification -- that people who have probably NEVER HEARD THEM are talking about measurements. And dissing one of the best sub-$10k loudspeakers that exists.

If you've never actually heard the equipment or loudspeaker under evaluation, you're in no position to make any remarks about the findings of those who've spent considerable time with them.

Just my two-cents-worth -- Nice job Ken Micallef and of course, Greg Roberts!

Tom

Tom Gibbs's picture

Having spent about a month with the Volti Razz, I can unequivocally state that I found them to be quite tonally neutral. That said, they also offered my music choices a level of compelling realism that made for intoxicating listening sessions; regardless of whether the source was an LP, digital disc, or a streamed file from my library, or Qobuz. I was seriously sleep-deprived during their stay, so great was my enthusiasm. And while, yes, the first track I auditioned was Tool's "Chocolate Chip Trip" (quite a trip!), I listened to music of just about every genre during the review period, from solo piano to acoustic jazz, chamber music, choral, orchestral, vocals, metal, prog rock -- you name it.

The Razz disappeared into the soundstage in a way that very few loudspeakers can; it was effortless for me to suspend my disbelief and become one with the music. Having recently heard Volti's $20K Rival SE's at this year's Florida Audio Expo, I found the Razz presented a sonic signature on par with its much more expensive sibling. And felt that the $5K Razz offered a very generous helping of the power, finesse, unrestrained dynamics, and musicality of the Rival SE at one-quarter the price. And the Razz played very nicely with tubes or solid state gear; I didn't feel that either choice of amplification altered its presentation to a significant degree.

I can't comment on measured results versus actual performance, but I can say that if you're seriously auditioning a horn-based loudspeaker design in the $5K price range, you should definitely add the Razz to your short list.

Bogolu Haranath's picture

May be you (TG) could listen to $5k/pair Revel Performa F208, reviewed by Stereophile, and write a follow up :-) .......

Anton's picture

https://www.stereophile.com/content/hoisted-your-own-petard

;-D

Bogolu Haranath's picture

Price is the same ..... Why not do a comparison? :-) ......

Anton's picture

Go for it!

Bogolu Haranath's picture

It would be better if TG does the comparison review and publishes it ....... Then, many 'inquiring minds' would know :-) .......

Hawk's picture

I am a current owner of Volti Razz speakers serial numbers 11 & 12 in the standard mahogany finish at $5K for the pair. I find them handsome, very musical, dynamic, and efficient. I drive them with a Prima Luna DiaLogue Premium HP Integrated Amplifiier ( 8 X EL34’s) with two sources. The first is a VPI Aries 1 with Hana ML cartridge into either a PS Audio Stellar Phono preamp or Manley Chinook SE phono preamp. The other source is an Audiolab 6000CDT cd transport into a Border Patrol SE DAC.

I really love live music and have been fortunate here in the metro Washington DC area to have access to the amazing US Military bands and orchestras as well as a great selection of venues from Blues Alley and Wolf Trap to Merryweather Post Pavillion offering rock, pop, jazz, symphonic, and country bands. Now at home with nearly everything closed to COVID, I’m spending more time in front of my stereo to get my music fix.

My Volti Razz speakers make instruments sound authentic. The music is so enjoyable and makes me want to listen. I have problems reading or multitasking because I want to put down what I’m doing and just listen. Lately I’ve been impressed by how the Razz’s make the Blue Note Tone Poet series of albums with various artists like Lee Morgan, Grant Green, Wayne Shorter, Hank Mobley just come alive. The pianos sound like pianos; saxes sound like saxes and the soundstage is tangible with lots of air and life. Additionally, the Razz’s are revealing of system changes. I immediately noted changes between my Prima Luna and a 300B amp; between the triode and ultra linear settings on the Prima Luna; and the difference between the PS Audio and Manley phono preamps. It is also easy to hear the impact of cartridge loading adjustments that I can change from a remote on the PS Audio. I first heard Volti speakers at the Capital Audiofest and really gravitated year after year to what Greg was able to achieve with his designs. His rooms always produced great music making me come back for more. There is no question that measurements are a big help for designers to baseline their products and gain a better understand what happens when they begin the iterative tweaking process to get the sound they want. PS Audio’s designer, Daren Myers, talks passionately about the importance of listening. His first prototype of his PS Audio Stellar Phono Preamp had low distortion and measured great but sounded to him a bit closed in and didn’t give him that first one note impact he was seeking. He focused on listening and redesigned much of the circuit to sound significantly better but not measure quite so well.

Some may very well see my system as very flawed from the analog front end that will not come close to measuring as good as a digital one, a tubed amp that again will not measure as well as solid state, not to mention my 50+ year old ears that don’t perform as they used to. But I’m so very pleased with my Razz speaker purchase and am achieving the best most enjoyable sound I’ve ever had in my home.

a.wayne's picture

Congrats Hawk ,

The full essence is to enjoy one’s setup and its obvious you do , enjoy in good health my man ..

Regards

Volti's picture

I'm happy for you Hawk. That's what the hobby is all about. The enjoyment of listening to music. I'm glad you 'get it'.

Thanks for supporting my small business. Please let me know if there's anything else with your system I can help with. I love helping my customers refine and improve.

I hope you enjoy your speakers for many years.

Greg Roberts
Volti Audio

a.wayne's picture

Good work John , a true gentleman and a scholar , protection of the innocent at all cost .. :)

BlackH20's picture

"Looks" like some Klipsch knock-offs, stuck in the 1970s, for $20K, not going to bother to listen, just go get a brand new pair of KornerHorns, yes with "real" wood also.

Volti's picture

I sell direct to my customers, because with dealer markup they would sell for FORTY LARGE.

LOL.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

Seems like a great business opportunity ....... Buy from GR for $5k and sell it for $40k :-) ........

Volti's picture

Hey, wait a minute, I want to get in on that!

Greg Roberts
Volti Audio

rschryer's picture

They're five large.

BlackH20's picture

Volti Audio's room at the 2020 Florida Audio Expo showcased the company's newest offering, the $20k/pair Rival Special Edition hybrid horn loudspeaker. With a custom cabinet and exotic Bubinga wood veneer, it easily counted among the best-looking loudspeakers I saw at the show.
Read CNET's review where the builder fell in love with Klipsch. Are they better than Klipsch? I don't know, do you?

ganyc's picture

I've heard the Volti speakers at two different RMAF shows. In both instances Volti paired the Rival SE with Border Patrol electronics. I walked into their room with my usual bias against horn speakers. I walked out with a different point of view. For me, beyond anything else these speakers are fun. They were playing "In the Buzz Bag" by the Brooklyn Funk Essentials. The sound had a presence and tone that immediately put to rest any silly notions I had about horn speakers. They just sounded great.

Volti's picture

Someone not only heard me playing BFE, but they actually know the band!

I thought I was the only one.

I get funny looks from my room partners when I play that stuff at shows. lol.

Greg Roberts
Volti Audio

PS - I miss RMAF

avanti1960's picture

minimizing enclosure resonances- few speakers perform this well at any price. Since coloration was a deal breaker for me with the Klipsch Forte III, I would love to hear the Razz. Impressive.....

Volti's picture

I didn't really set out to eliminate the resonances. When I develop a new speaker, I add and take away bracing and damping and listen to the results. I'm listening for a certain liveliness to the sound, and then I'm listening for when that liveliness goes away and the sound becomes dead. Damping material will affect the sound of a cabinet when placed in different sections of the cabinet and where it is placed near the woofer driver, and it is all audible with music playing. It's an exercise in patience and hard work pulling drivers, changing damping, testing, and listening - and doing this over and over and over again.

I did find that overall the Razz needed more damping than the Rival, which surprised me. I don't really know why this is. I suspect it has something to do with the closeness of the cabinet walls to the woofer.

Anyway, I appreciate the compliment.

Just a thought though - what if Klipsch has the Forte III cabinet resonating just the way they want it to? What if that's part of the sound they have created? I'm smiling as I type this, but I'm also serious. Anyone who has listened to the Klipsch La Scala I with and without added bracing on the sidewalls of the bass horn will tell you that they sound leaner with the braces.

Greg Roberts
Volti Audio

Bogolu Haranath's picture

TG could review the JBL K2 S9900 ($30,000/pair) ..... See, Hi-Fi News and What Hi-Fi reviews :-) .......

FredisDead's picture

I too walked into the Volti/TWL/BP room at Axpona '19 thinking I would probably not like what I heard and I was bowled over. I liked the sound so much that I looked at the display models (Rivals) and was disappointed and yet relieved that the demos had already been sold at a show-special price. I might very well have bought them. Wine drinkers tend to go from zin and cab to more delicate thinking-man's wines like Riesling and Burgundy So it is with audio-with time and experience, tastes and priorities change. These speakers are accurate to the spirit of music, not the building blocks of music. The fact that the enclosures are crafted to true artisan levels is just a bonus. You need to see then in person to appreciate their beauty. I already have two set of new speakers I rotate in and out of my system due to each having totally separate suits of strengths, Devore O/93's and Spendor D7.2's. My listening room is on the small side. That said, I am sorely tempted to buy a pair of Razzes. And no, I have no connection to Volti (or TWL or Border Patrol). Mr. Roberts-thank you for doing what you do. High end audio needs more people like you.

Volti's picture

sharing this.

Greg Roberts
Volti Audio

prerich45's picture

I don't have any speakers designed by me listed in Stereophile Recommended components, let alone Class A. However just reading the comments, I'd like to suggest that Greg allow Harman to put his product into the Spinorama and see what trained ears think (as it is truly a blind test). Also the one thing that most of us don't consider is our auditory health. I make it a point to try and have my ears cleaned 3 times a year. Also, because of a previous profession I have tinnitus in my right ear. Age can be a factor as well. The biggest, most subjective piece of equipment that you own, are your own ears.

Kal Rubinson's picture

You are conflating two different things when you "suggest that Greg allow Harman to put his product into the Spinorama and see what trained ears think (as it is truly a blind test)."
1. Spinorama is an objective measurement of speaker output in three dimensions and presented as a series of FR graphs for different spatial outputs.
2. Harman's blind test procedures (with trained and/or untrained ears) are based on subjective assessments which are statistically analyzed.

Nonetheless, I agree that both would be interesting although most of the Spinorama information is already included int JA's published measurements.

Bogolu Haranath's picture

Do you (KR) know whether, Harman used/uses any dipole speakers like Magnepan, Martin-Logan, Quad electrostats etc. in their 'blind listening tests'? ...... Just curious :-) ......

Kal Rubinson's picture

I do not know. I did see racks of speaker boxes stacked between the labs and they bore many familiar names. I cannot recall any dipoles but, then again, I wasn't looking for them.

AJ's picture

Harman has tested older Martin Logans and Quads as well, with published results. Unclear whether they have tested more modern/improved versions (possibly unpublished).
This had lead poorly informed/prolific internet audio site posters to erroneous conclusions about bi/multi directional radiators and Harman style listening test rankings.
Oblivious to the fact that one of, if not the highest ranked speakers ever during Toole's NRC days, was the Mirage M1 (His once personal speakers).
Fig 4 tells the tale for those who follow the research
https://www.stereophile.com/content/mirage-m-1si-loudspeaker-measurements

cheers,
AJ
Soundfield

Bogolu Haranath's picture

Mirage M-1si is a 'bipolar' speaker ..... It not a 'dipole' like Martin Logan, Magnepan etc. :-) .....

prerich45's picture

I know that Martins were tested for sure.

prerich45's picture

Yes..I see what I did LOL!!!! Well, it's like GI Joe, now I know...and that's half the battle!!!!!

prerich45's picture

Ok, I've gone through the reviews of Greg's speakers (and yes he's a mastercraftsman on woodworking) in the pages of Stereophile and what I find in common is that even though they don't measure well, they consistently sound great! I know, I know ...if it measures well it should sound well, and if it measures badly....., but it appears to be some "straight up sorcery -Cyborg Teen Titans Go" going on with Greg, as he puts out satisfying product after satisfying product. Is it in the voicing of the speaker? Has he latched on to a way of hearing that's pleasing to most human ears? This can't be coincidence, as I doubt that Greg has the type of cash to pay Stereophile for successful reviews - even if some of his speakers have 5 figure price tags. Most of his work appears to be done by hand (I've watched him through the years of Klipsch upgrades and the like). There's got to be something he's discovered - as they say hearing is believing. Ultimately, it's what the customer prefers...and Greg has found a nice comfy spot that defies measurements.

Bogolu Haranath's picture

Instead of 'paying cash' to Stereophile, if we pay cash to GR, he may tell us the secret recipe formula for great sound :-) .......

prerich45's picture

Yes indeed LOL!!!! He just might....but a cook never tells what's in the secret sauce until they've got the maximum personal profit from it, then they go to the mass market for the big bucks LOL what some call pickin' pennies (the ideal that there are more pennies available than dollars...but if you get all the pennies....)LOL!!!!!!!

Volti's picture

I'm content with simply making a living at this business, and there are times when I wonder if that is even possible.

I want to respond to folks here who keep referring the Razz measurements as being 'bad'. I don't think the Razz measurements look bad at all. I think audiophiles have been trained to think that speaker measurements need to look a certain way to be good, and anything else is bad. And that's simply not the case.

The measurement parameters that anyone uses as a way to evaluate the sound of a speaker (no matter how widely accepted) are just someone's opinion about what speaker measurements should look like.

They are also woefully insufficient at telling us what a speaker will sound like.

I have my own way of doing things thank you very much, and it's working out quite nicely.

Greg Roberts
Volti Audio

prerich45's picture

When you went big time Greg...I also wondered if it would be worth it. That was a tough time when you decided to make the move from New England to I think Tennessee? I wish you all the luck, and it appears to be moving right along. I think I may have mentioned before but I actually believe that the biggest subjective unit we have are our ears...because of audio health per say. We're all in different phases of our lives and have been subjected to different things (like listening to loud communications signals in my case). So shoe horning a speaker for everyone is IMHO impossible. Just keep doing what you do and those that like it will buy it. Those that don't ....won't. Glad to see you're making out a-ok though!

BadgerBeat's picture

I recently purchased a pair of Razz speakers from Greg--here's my initial take. They replaced a pair of Klipsch Forte IIIs.

Got them unpacked and quickly set up with quickest hook up in the house, the Naim Uniti Atom. In a word, awesome. I wasn’t listening to audiophile test tracks, just streaming whatever popped into my head. I started with classic 60’s playlist and bounced around from there. The initial setup was in more or less the same spot as the Klipsch, but more towed into the listening position. I’m going to move things around quite a bit, but for the first night, I wanted a similar setup to what I had been using previously.

What I loved about the Forte IIIs was their sheer visceral impact. They are dynamic and fast in ways that just works with what I listen to. I ran them with the Atom and also with a Manley Stingray fed by a Bluesound Node 2i through an Ayre Codex. My only real complaint was as the volume went up, there was a noticeable upper midrange “glare” on music that wasn’t ideally recorded. One way to partially mitigate that was to really limit the tow in on the speakers. It did this in both my setups. It was largely mitigated when I used an Innuos Zenith MKIII as a source for a few days in May (my next purchase, BTW)--although I still wouldn't recommend towing the Forte IIIs in even with the Innuous as a source.

So out go the Forte III’s and in come the Razz. The first thing I noticed is that the Razz are slightly less efficient than the Forte IIIs. They are in the ballpark but took a few more steps up the volume ladder to hit comparable levels. The spec on the Forte IIIs is 100db, while the Razz is 97db and whatever the actual numbers are, the 3db difference seems about right. At first blush, the Razz are visceral in a different way than are the Forte IIIs--they don't hit you in the face quite the same way as the Klipsch (which is more often than not a good thing). It's more of a song to song kind of thing than an overarching thing. If a certain song really hit you with the Klipsch it was often a different song that really hit you with the Volti’s. It’s one of my problems when reviewers go rolling through a set of test tracks, as they were more than likely picked because they sounded good on a particular system and ignores what might sound better on another.

What the Razz did better than the Forte IIIs was pretty much every other thing you could probably think of. The bass response on the Razz is much better. For some reason, you look at the woofer on the Forte III’s and the giant passive radiator on the back and you expect a lot of bass, but it really doesn’t happen. Maybe pushed about 10” off the wall, but leads to other issues. I never minded the bass on the Klipsch but the Razz are clearly more prominent in the bass response. What really stands out is the integration between the upper bass and lower midrange. I'm hearing details in this area that I NEVER heard out of the Klipsch.

The imaging is also much better on the Razz. They throw a nice wide sound stage in which all the images are clearly firmly locked in place. That just isn’t something the Klipsch did all that well.

For me, the biggest improvement is how real the instruments sound coming out of the Razz. The horns sound like they are in the room with you. Acoustic guitars are right on. Combined with better detail coming out of the Razz, this is where the two speakers are the most different. The number of times I heard a detail or a separation of voices on the Razz that I have never noticed on the Forte III’s was astounding. I say that the Klipsch sounds like live music at Iota or Gypsy Sally’s (RIP to both ☹️) while the Volti sounds like live music at the Birchmere or The Hamilton. Sorry for the DC reference, but those here should know what that means. And there is no upper midrange glare of any kind on the Razz. The volume goes up and it’s just as listenable as at lower levels.

So if I were bouncing between spending $4K on the Forte IIIs and $5K for the Razz, it would be an obvious choice for me. The Razz are simply better speakers. They sound more like the actual instruments. In addition to sound quality, the build quality is also much better on the Razz (and I have no issue on the build quality on the Klipsch). I’ve seen the unfinished Razz cabinets and it's some impressive work. The Razz are about 100 lbs a speaker while the Forte IIIs are about 72 lbs (The Razz are taller but not as wide or deep as the Forte IIIs). Full disclosure is that I actually upgraded to a specialty veneer (Bosse Cedar) so my set was $6K rather than $5K. But they are true artisan products that will be in my house for years to come, so well worth the upgrade.

For background my idea on speakers is that I could care less how they measure, it's all about how they sound. I think trying to correlate the two in any kind of absolute sense is laughable. If you are a measurements guy, great, go buy another speaker. But I know for a fact that the Volti audio owners that I know are all completely thrilled with their speakers. I also know that I don't see any Volti speakers listed on USA Audiomart or Audiogon, but I see lots from Revel. People who buy speakers from Greg tend to keep them. I wonder why that could be!

Hawk's picture

BadgerBeat,

Enjoyed your first evening impressions which match many of my own. And that DC venue analogy, spot on! I had a great experience at the Hamilton last fall. The Razz's don't have a long run in period but you'll notice an improvement in focus and sound stage with all of the other attributes that make instruments sound authentic remain in place. I look forward to reading your updates as you put additional hours on them. I'm sure they're gorgeous. Like you, after that exciting moment of first connecting them up and having that initial listen, there was not a second thought on my decision to purchase Greg's best value speakers.

justincz's picture

stay far away from this speaker

RN013's picture

What I really miss about live audio shows is walking into a room where I have no preconceived notions about the products because I've never heard them and maybe even never read about them and having a "wow" reaction. That is what happened to me with the Volti Rival loudspeaker. They were musical, they were captivating, they were beautiful and they just sounded good.

I was shocked when I found out they were horns....I was pretty sure from all the negative publicity that I didn't like horns..even though I hadn't really sought them out to listen to them. A year later, I heard the Rivals again...and I wasn't quite sure what to expect but again the sounded great....more like live music and less like a good home audio system.

Two things I've come to believe is that Dr. Floyd Toole's measurement methodology can be very helpful for designers to avoid making speakers that the masses don't like. It can also be helpful for buyers trying to make sense of the hundreds of choices. But it can't tell you whether you will like a speaker in your home with your equipment...and in that regard it can create bias.

If you remember that 70-80% of people will prefer the "more accurate" speaker when listening in a controlled environment, it also means that 20-30% won't. It is not a matter of right or wrong, it is a matter of preference.

Unfortunately, there will be some that because of measurements, won't walk into that room at the next audio show and listen to something that may very well have given them a "wow" experience.

Based on the Rivals, I'm pretty sure that the Jazz sounds darn good and definitely worth hearing before deciding whether it suits your taste or not.

gasolin's picture

Omg that's a bad frequency responce

jimmyt's picture

During the 25 or so year period when I went to a lot of concerts I should have protected my ears better, and I was also in the construction business for 35 years which did not help. AND I had stapedectomy operations in both ears (likely hereditary) that I found out 20 years later was also guaranteed to give me tinnitus. But reading Stereophile and Absolute Sound for 25 years taught me a little about listening and I can still very much enjoy music. I could never get used to the K-horn tweeter even swapping it for a Crites replacement that did not help. Other modifications I made to that speaker helped but eventually it had to go. I rarely payed much attention to the speaker measurements in reviews, I couldn't (be bothered?) let them determine if a speaker was right for me. Now I just skip to the end and read the summation. I want hear what I heard at all those live concerts. I ended my subscriptions when Art (who named his mag Listening) passed so suddenly. If you got the measurements stuck in your head I would think that's worse than tinnitus. When I go to a concert now I know if it's good sound or not. I don't run up to the board man asking for measurements. I hope GR hits a low spot in sales where he has to search high and low for "usable but not sellable" stuff (woods and drivers) laying around to make a "Funky" Razz for half price that I can afford. I listen with my eyes closed with no lights on but it could be daylight. Lead or gold shines the same. And both 9:30 clubs and both Birchmeres sound (sounded) good to me. But Dave Alvin doing the whole Ashgrove record at it's release at the Iota was one special stage pounding night for me.

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